This invention relates to a flexible cover support structure and, more particularly, to such a structure particularly adapted to accommodate size variations in the covers utilized therewith.
There is illustrated in U.S. Pat. No. 3,333,373 issued to Taylor on Aug. 1, 1967, and entitled Portable Folding Camping Cabin or House a portable enclosure which includes a series of flexibly interconnected rigid panels and a dome-shaped roof. The roof support comprises a plurality of upwardly-bowed, tube-like members extending radially from a central hub. These members include tips at their extremities specifically adapted to engage an encircling cable and to pass through grommets in the depending skirt of the fabric coverings to retain the same in overlying relationship with respect to the supports.
Assembly of the fabric cover to the structure is effected by passing the grommets over the tube tips at circumferentially spaced locations about the enclosure. This assembly procedure, when nearing completion, becomes increasingly difficult since it is necessary to stretch the fabric past the end of the tube so that the tube tips can pass through the grommet therein.
It is desirable, of course, that the cover be snugly retained on the supporting structure. It must be smooth and taut not only for aesthetic purposes but for functional reasons as well. These requirements, when combined with the requirement that the cover be stretchable radially a sufficient distance to permit passage of the tube tip through the grommet, have resulted in the past in a very narrow range of diameter tolerances for the cover. These tolerances have resulted not only in manufacturing difficulties but in consumer difficulties as well.
The fabric utilized for covers of this type, more particularly, has been found to be susceptible to shrinkage despite the utilization of preshrinking techniques prior to manufacture. This shrinking, which is aggravated by the wind, rain, sun, and other climatic conditions, typically takes place for a two- to three-year period after the cover has been in use. Where a particular cover was on the minimum side of the tolerance range at the completion of manufacture, this field shrinkage has interfered markedly with the ease with which structures of the type under consideration can be erected. It has resulted in some situations, in fact, in torn covers and covers which simply cannot be stretched a sufficient distance to pg,3 permit the grommets to be passed over the ends of the tube tips.